Process for manufacturing artificial silk and other filaments by applying electric current



Patented Jan. 22, 1929.

UNITED STATES PROCESS FOR MANUFAOTURIN G ARTIFICIAL SILK AND APPLYING ELECTRIC CURRENT.

PATENT OFFICE.

KYOTO, 'JAPAN, ASSIGNOR T JAPAN.

OTHER FILAMENTS BY lib-Drawing. Application filed March 14, 1927, Serial No. 175,438, and in Japan August 3, 1926.

This invention relates to a process for manufacturing artificial silk and other filaments, characterized by applying electricity to solution of the raw material while or beore spinning them.

The object of the invention is to make the colloidal solution of the raw material inigi'ate in one direction by passing an electric current through the solution which is divided and a cathode section by a capilinto an anode lary, such as a spinning nozzle. By utilizing this migration speed caused by the electrical cndosmose or cataphoresis, together with the speed due to the pressure of compressed air and pump as in the case of ordinary practice, the speed of the solution is very much accelerated and increased, and 'at the same time the silentdischarge may take place between the solution and the coagulation liquid, decomposing such a sort of gas as is often produced in ooagulation.'for instance, hydrogen sulphide liberated from viscose, into some soluble sulphur or oxygen compounds and thus there is no unhealthy gas of disagreeable odor and it serves to protect the health of operatives very easily and surely.

It is evident that the colloidal solutions are migrated under the influence of a fall in potential, and that the quantity of a given solution carried through time depends upon its viscosity and varies directly according to the current strength and is independent of the area of the capillary. As the discharge of the electric current of high frequency and high voltage like an induction current is usually intermittent according to its frequency and the nature of its electrodes is also definite, the same effect, as in the case of direct electric current of high voltage, will be obtained duction current of high frequency. And also, the higher the frequency ous it is to human body. Therefore, as the solution of artificial silk like viscose is a negative colloid which migrates toward the cathode, if an electrode be placed in solution of the material of artificial silk or other filaents and another electrode in the coagulaon bath in the case 7 tioninigrates toward cathode through the spinning nozzle owing to electric cataphoresis. If high voltage of induction current be applied, the speed of migration will be considerably increased, which accelerates duced no unhealthy a capillary in a definite by applying an inis, the less danger-' of spinning, the solu the flowing speed due to the pressure of compressed air and pump, and accordingly the spinning speed i. e. the production of artificial silk or other, filaments-Will also be increased. Further, as the flow of particles suspended in the solution tends to make the configuration of particles in regular rows, the particles are coagulated in a regular and parallel order and the strength and other physical properties of the product will be much improved.

During the coagulation period the gases will evolve fromthe surface of the spun filaments in the case of viscose silk and the passage of electricity is separated by such evolved gases, in consequence of which the silent discharge of electric current will take place continuously until the spun filaments reaches the surface of coagulation liquid from the spinning orifice; by this silent discharge, ozone gas is produced and such a sort of gas as is often produced during the coagulation, for instance, hydrogen sulphide, is decomposed into soluble oxygen compound and dissolves in Water. Thus, there being progas of disagreeable odor, the ventilating apparatuses, the masks, the ozonizer etc. hitherto used for the protection of health, can be entirely dispensed with.

When coagulation is eifected in twostages as in spinning arrangement of so-called bobbin system, the same effect will beobtained by the anodes in solution of the raw material and on the surface of winding bobbin, and the cathodes in the first and second coagulation baths respectively.

In this invention an induction current of electricity is applied, although the same effect may be obtained by the use of, direct electric current, because it is evident that the effect is somewhat inferior to the one obtained by the application of an induction current which is considerably difierent from that in potential difference.

The following example will illustrate how the invention may be carried out in practice, but the invention. is not limitedto this example.

Place an anode in a spinning nozzle of an artificial silk spinning frame and a cathode in coagulation bath. The induction current having a frequency of 4,800 cycles per minute is regulated to a spark or air gap of to millimeters. Make the initial pressure of compressed air 1.2 kg. per sq. cm. to make it rent, the effect of pulsation will be much finer I maintain about 0.8 kg. per sq. cm. near the than that of spinning pump and the size spinning nozzle. First try to spin without filament will be more uniform. Furtherdischarging the electric current, then we will -more, the particles of the colloidal grains in find'thatthe spinning is verydifficult withthe solution are a gregated in regular an out keeping thespinnmg speed within to parallel "order an ,the physical quality ofmeters per minute, owing to the breakage the product will be very much improved.

of thread or filament-s. However, when the. I In short, this invention has the special fealndllCtIOIl current is discharged, the spinning ture that the flowln g movement of solutionpf goes very easlly and even at the speed of artificial Sllk of great viscosity can be 1nto meters per minute a thicker thread than creased and accelerated in spinning process, that obtained in the previous case can be thus increasing the efiiclency of ,productlon spun out. With spinning nozzle to spin and at the same time saving spinning pumps single filaments of 6 to 7 deniers 111 common or making them simply serve as supplement, case, single filament of 25,, 12 to 1-5, and-8 t0 and all the devices for removing or ozonizing 10 deniers can he obtained at the speed of the poisonous gases can be entirely dispensed 15-to 20, 30, and 45 meters per minute respecwith. In this way we can economize the tively. From these results wecan easily com costs of machineries in spinning departmentsider that'the spinning speed may be 1nas well as the maintenance expenditure and v creased more. Further, under the ordinary also can easily and surely protect the health only as a meter and does not need such a spinning pressure, 1. e. 2 to 3 kg. per sq. cm., of operatives. the spinning speed may lie-increased to 7 0 I claim to meters per minute according to the Process for manufacturing artificial silk condition of the colloidal solution of artificial and other filaments, characterized by caussilk and the production of spinningframe ing the raw material solution to migrate,

will be nearly doubled and at the same time which consists in placing an electrode in a the spinning pump with which 'we suffer solution of the raw material and'another always to repalr very soon'by its wear, serves electrode in the coagulation liquid and then e passing thereto an electric current, especially and precise workmanship as now we can find an induction current. s in practice. The pulsation of solution is In testimony whereof I have 'aflixed my mainly governed by the voltage. and the numsignature. 7 her of frequency of current used, and if we apply high voltage and high frequency cur- KIYOHIKO HAGIWARA. 

